Since June 2000, the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory has delivered the first collisions between Au nuclei at the highest center of mass energies achieved in the laboratory to date. PHOBOS is one of four experiments studying the Au + Au interactions at RHIC. In this paper we will describe the PHOBOS experiment, and discuss some of the current physics results obtained for Au + Au collisions at √SNN = 56 and 130 and 200 GeV. They include the study of the charged particle multiplicity as a function of pseudo-rapidity and centrality, and the measurements of the antiparticles to particles ratios. The observed charged particle densities near mid-rapidity are higher than previously measured in any nuclear collisions. Also the rate of increase of the mid-rapidity particle density with energy is faster than that for nucleon-nucleon collisions at comparable beam energies. Finally, the antiparticle to particle ratios indicate the creation of a nearly baryon free zone at mid-rapidity.
|Number of pages||9|
|Journal||Acta Physica Hungarica, Series A: Heavy Ion Physics|
|State||Published - 2002|
- Antiparticle to particle ratio
- Centrality dependence
- Charged particle multiplicity
- Heavy-ion collisions